Something is wrong in either the horizontal or possibly the vertical
counters - I'm rusty so can't say for sure which. For this sort of thing
I use a logic probe and TTL reference books to see if outputs are valid.
Or I use my Bugtrap Logic Comparator which is a great tool and helps
avoid a lot of shotgun repairs...
I fix those boards, but have way more tools at my disposal than the
casual hobbyist.
You can learn how to fix game boards, but it takes time and a lot of
reading and thinking.
John :-#)#
On 2018/07/19 1:09 AM,
horde5150@gmail.com wrote:
I hope someone can help. KLOV and FB groups are silent.
I'm really close. I am trying to restore a Centipede arcade. Board has some issues. Already replaced the PCB caps, replaced the POKEY to restore right-side mushrooms and correct most sound (there's a loud hum when displaying VIOLET text in Attract mode)
, and replaced one physically damaged EPROM at D1.
** Problem is, none of the game sprites will travel up and down (while displayed Vertically). They will only move left and right.
Upon startup, there are two visible centipede segments at top. They are taking up 2 lines. They just go back and forth without visibly descending - they are though. The spider travels across the screen making stops randomly, but never "bouncing"
diagonally like it should. Scorpion can be seen moving across the screen at the VERY bottom, and affecting mushrooms in the field.
The player can move left and right, not up and down.
The player can still lose a life from centipede and spider even though it appears to never make contact.
I've swapped H6 and F6, A5 and B5 with new LS83 and LS163s and saw no change.
Test mode gives no beeps for RAM error.
What am I missing?
I also have an ancient scope and logic probe if there's anything I can look for.
Video Description: https://vimeo.com/279794693
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John's Jukes Ltd.
MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
(604)872-5757 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."
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